The present invention relates generally to the preservation of dairy products from spoilage and, more specifically, to the use of natural plant extracts to delay oxidation and extend the shelf life of milk and milk powder.
Milk is a complex biological system consisting of fats, proteins, minerals, vitamins, carbohydrates and water. Milk powders contribute nutritionally, functionally and economically to a variety of food formulations including bakery, confectionery, dairy, recombined milk, meat, nutritional beverages and prepared foods. Whole fat milk powder has relative high fat content (26%-40%) and enriched in vitamins, that not only serves as ingredients in processed foods, but also is popular nutrient source in many third world countries1. Recently, whole milk fat has found to be a healthy form of fat which could promote human health2, so it is expected that the consumption of whole fat milk would increase. However, the relatively high fat content makes is prone to oxidation, which can in turn decrease the nutrition value of milk fat, as well as affecting the flavors of milk. On the other hand, in many third world countries, proper packages and controlled storage conditions are limited, which in turn further limit the shelf life of whole fat milk powder. Effective ingredients are needed in whole fat milk powder to slow down oxidation and protect the nutritional and functional values. Synthetic antioxidant, butylrated hydroxyanisole (BHA), is allowed in whole fat milk powder in EU and US However, the general trend to move away from using synthetic ingredient drives this study and many other efforts to identify more natural ingredients, or active packages3 to delay milk fat oxidation. The objective of this study is to identify multiple natural plant extracts or naturally derived reagents effective to delay milk fat oxidation to replace synthetic chemicals that are currently used in whole fat milk powder.